Re: [tomato] mycorrhiza and environmental stress...

Thomas Giannou (
Wed, 3 Mar 1999 22:53:04 -0800


One thing I noticed is that during the month of May last year when it was
cold here, untreated plants stayed dormant.  The treated plants basically
seemed to ignore the cool weather and grew fairly well.  In this particular
area, in the summer it is hot and dry.   During the hotest part of the
summer all the treated plants really grew quite well.  The untreated plants
seemed to suffer from the heat.  Their leaves would burn and they would have
a much more difficult time retaining water in the heat.

I also noticed an increased level of earthworm activity in the garden around
the treated plants.  I was thinking of mulch mowing the lawn this year, but
I think I'll take the clippings off the lawn every other week and put them
on top of the soil in the garden for the worms to eat.   I mow once a week
and that way the worms in the lawn area will get some dead grass to eat at
least every other week.  When I had my lawn treated with a chemical lawn
care company, they told me not to do that because the weed control chemicals
would have a detrimental affect on the garden.... probably kill most of the
plants there... or introduce toxins into the food.  But now, it should be
just fine.  I put a couple of lawnmower catcher bags of grass in around the
Raspberries in the fall and it is all gone... I am sure some of it
decomposed, but the area where I spread it out is now bare with no
detectable clippings present.  I was reading someplace about the fertilizer
effect from the worm castings could account for about 30% of the nitrogen
thats needed to be added each year.   The manufacturer of Bio-Vam has told
me that when organic fertilizers are applied, to do so at 1/3 the
recommended rate of the fertilizer manufacturer.   They say one to two
applications of Organic Fertilizer per season are adequate.   If that is
true, then the earthworm contributions are equivalent to one fertilizer
application during the growing season when mycorrhiza is plentiful in the
roots of the plants.  The earthworms seem to be fairly active now, but it is
too cold to plant anything outside right now.   It seems to me, that with
all of those earthworms eating the mulch that the need to put on fertilizer
will diminish... perhaps even be eliminated.  My brothers lawn is just
peppered with worm holes... looks like it has been aerated.  I think I'll
see if I can convince him not to add any fertilizer and to mulch cut his
lawn and see what happens.  I haven't really thought about this particular
thing before, but if it works, it could reduce the amount of money people
have to spend on fertilizers each year to just one or maybe no treatments.

Thank you for the reference you gave me.  I'll read the infomation and see
if there are any ideas I can use or if there are some things I may have to
tweak along the way.

Best Regards,
Thomas Giannou
Spokane, Washington

-----Original Message-----
From: Olin <>
To: <>
Cc: Doreen Howard <>
Date: Wednesday, March 03, 1999 10:02 PM
Subject: Re: [tomato] mycorrhiza and environmental stress...

>-----Original Message-----
>From: Thomas Giannou <>
>To: <>
>Date: Wednesday, March 03, 1999 9:36 PM
>Subject: [tomato] mycorrhiza and environmental stress...
>>Yours is a situation in which I would advise trying to use a Mycorrhiza
>>inoculant  ...etc
>> ..
>Thanks for your thoughtful and complete post addressing my environmental
>situation and a possible aid to alleviating environmental stresses.  The
>only tomato plants I have yet to set out are involved in another trial and
>don't have enough specimens available of the same varieties of the trial
>plants for comparison with another Mycorrhiza control group to be
>statistically significant.  Including another variable at this time could
>also make the current trial results inconclusive.  But I certainly would
>like to try it at another time.
>I received a report last year, "Mycorrhizal Fungi Experiments" from Doreen
>Howard on the results of her 1997 tomato tests.  Although we were both in
>the same USDA cold hardiness zone (9b), the climate and environmental
>considerations were very different (hot and humid versus hot and dry) such
>that I did not believe her conclusions would be applicable to our desert
>climate.  Her report is archived at
> and it generated a
>lenthy thread on this list which I don't believe necessary to repeat.
>Olin, Phoenix AZ